When does the nudity begin?
Having entered the men-only fifth floor of the Dragon Hill Spa, I've followed a couple of locals through a brightly lit foyer past a snack bar, into a locker area.
Although we've paid an entry fee we've not been issued with towels, so I'm not sure of the next step.
Thank god for smartphones - I pretend to be checking mine while waiting to see what my unwitting companions do next.
As I inspect imaginary text messages, they strip off completely, then wander back to the foyer wearing nothing but the numbered wristbands which open the lockers.
OK. When in Rome... or Seoul. I strip, then wander cautiously through the foyer. No one bats an eyelid. So far, so good.
Then I spot a door, which leads to a long, dimly lit room lined with showers, sit-down washing stalls, hot baths and a sauna. And there are lots of naked men here, moving between each area.
This is the world of the jjimjilbang, the traditional South Korean bathhouse. In previous centuries they were a practical neighbourhood facility but with the advent of modern home plumbing they reinvented themselves as 24-hour leisure centres.
Dragon Hill is an extreme example, occupying a six-storey building. In its unisex areas, men, women and children are dressed in pyjama-like clothing and eat, drink, play video games, recline in massage chairs, or just nap on the heated floors.
The baths, however, are the heart of the jjimjilbang's appeal. After a thorough wash at one of the shower stalls, a strict requirement of bathhouse etiquette, I try the various baths. They're set at around 40 degrees, with the exception of one at 16 degrees, which feels like the Antarctic.
As always with mass nudity, anticipation is much worse than reality. After a few minutes I've forgotten we're unclothed at all, and wander toward an adjoining room containing massage tables.
A notice with basic English translation lists treatments, starting with a body scrub and ascending to massages.
One of the staff comes over to make a joke about our comparative sizes - he and I are indeed the Timon and Pumbaa of the Korean bathhouse world - and asks if I'd like the scrub (about $30).
What have I got to lose? A lot of skin, as it turns out. The masseur turns me this way and that on the waterproof table, scrubbing me vigorously with exfoliating gloves and periodically dousing me with water.
He finishes by applying what feels like raw alcohol to my now pristine back. It hurts. It hurts a lot. Then it hurts some more. I'm sluiced down once more, a soothing lotion applied, and I'm done.
A Chinese-American guy I'd been talking to earlier has a look at my back and confirms it is very red. I also feel much lighter, as if kilograms of excess skin have been removed.
As I don shorts and shirt for use on the lower floors, it occurs to me that these baths are the great equaliser in an otherwise hierarchical society. In your birthday suit, no one knows whether you're a CEO or a guy who works at a convenience store.
The writer travelled courtesy of the Korea Tourism Organisation.